A sample trial from each of the experiments, at complexity level 2, if all the stimuli were to remain onscreen, with the correct answer added. Stimuli were shown one at a time, in a reading pattern (left to right, then on the next line, etc.); each column was depicted in a different color. Presentation times were subject-paced. In Experiment 1 (panel A), stimuli in row 2 were compared to those in row 1; in Experiment 2 (panel B), stimuli for rows 2 and row 3 were compared to those in the row above it; in Experiment 3 (panel C), stimuli in rows 2 and 3 were compared to those in row 1.